Choose the appropriate lettered site or structure in the following radiograph of the wrist and hand (see Figure below). If the floor of the anatomic snuffbox and origin of the abductor pollicis brevis are damaged, which of the following bones is most likely to be involved?
High-Yield Explanation
The scaphoid forms the floor of the anatomic snuffbox and provides a site for origin of the abductor pollicis brevis. scaphoid marked in the given picture by B Boundries of Anatomical snuff box - posteromedially ( ulnar border) - extensor Pollicis longus Anterolaterally (radial border) - extensor pollicis brevis and abductor pollicis longus. floor - scaphoid, trapezium, base of 1st metacarpal and styloid process of radius. content - radial aery (Pulse can be felt by palpating radial aery against scaphoid bone.